Thrust balancing apparatus



OCt- 26, 1943 E. F. MILLER 2,333,031

THRUST BALANCING APPARATUS Filed Feb. 2l, 1942 WITNESSES: INVENTOR W E'RNssTFI MxLLER.

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ATTORNEY Patented Oct. 26, 1943 Y i i THRUs'r BALANCING APPARATUS.

Ernest F. Miller, Lansdowne, Pa., assigner to` y Westinghouse Electric & Manufacturing Com- Apany, East Pittsburgh, Pa., a corporation of I Pennsylvania Application February 21, 1942, Serial No. 431,791

6 Claims. `(Cl. 257-43) This invention relates to means for balancing moments and reactions exerted upon relatively rigid joints between `two pieces of apparatus resulting from moments produced by hydrostatic thrust in expansionujoints carried by. one of` the pieces of apparatus, and has for an object the provision of improved: thrust-balancing means for usetherewith. n ,Y

In certain steam condenser installations, particularly cooling tower applications, the circulating Water 4rn'essure acting through `expansion joints in the Water supply and discharge conduits creates harmful bending` moments on the` joint between thecondenser exhaust inlet and the turbine casing. Somecf thesemoments tendlto open the jointbetweenthe turbine and condenser and create Vdistortion in the turbinel `structure while others produce a shearing action at the same location. 'Il1ereforeit is anobject of this invention to provide meansfor counterlacting or reducing `the moments and. reactions .onthe joint to a'point where they have no` serious effect `upon the .turbinecondenser joint.

These and otherobjects are effected' b-y the invention aswillbe apparent from the following description and claims taken in accordance with the accompanying drawing, forming a part of this application, in which: i

In the drawing, Fig. 1 is a side elevational View of a condenser embodying the present invention, a portion of the structure being broken the sake of clearness;

Fig. 2 is a transverse sectional view taken along the line II`II Iof Fig. 1, looking in the direction of the arrows;

Fig. 3 is a view similar to Fig. 2, with the balancing expansion element located in a slightly diierent position with respect to the apparatus; and,

\ Fig. 4 is a diagram relating to the construction illustrated in Fig. 3.

Referring now to the drawing more in detail there is shown, at I0, a condenser comprised by a shell II having an exhaust steam inlet I2 at the top and a condensate outlet I3 at the bottom. The condenser is connected to the underside of a turbine I4 by mating ilanges I5 and I6, carried by the condenser and turbine, respectively.

A plurality of tubes I8 extend longitudinally of the shell and have their terminal portions supported by end tube plates I 9. Waterbox structures 2u and 2I are associated with the tube plates I 9, the waterbox having a partition 22 dividing the interior thereof into an inlet chamber 23* and an outlet chamber 24, resulting `away for in now of condensing water through the tubes I8 in two passes, the waterbox 2| providing a reversing chamber. The waterbox 2i) is provided with inlet and outlet connections 25 and 21 which are connected, by expansion joints 28 and 28a, respectively, with water-supply and discharge conduits' 28 and 30, respectively.

The structure so far` `described may be considered Fas conventional. The hydrostatic thrusts exerted on the condenser through the expansion joints 28 and 28a would, if not counter` acted or balanced, produce momentsv and reactions cn the relatively rigid joint between the condenser and turbine. In order to reduce or `eliminate these reactions on the condenserturbine joint', the present invention contemplates the provision of an expansion element 35 positioned "between a rigid or xed support 36 and the condenser waterbox 2D, communication being provided between the expansion element 35 and the interior of the waterbox 20 by a conduit`3'l.

In order that` any pulsations present in the water flowing'through the waterbox may be prevented from reachingthe expansion element 35, the conduit 31` connectingthe element with the waterbox maybe provided with a restricting member or partition 38 having a relatively small-opening 38 tl'ierethrough.` This arrangement will permit any gradual pressure' change occurring in the waterbox to be received inthe expansion lelement 35, while preventing any rapid pressure changes such as pulsations being transmitted thereto.

In the arrangement shown in Fig; 2, the expansion elementJ 35 has been so located as to counteract or eliminate bending moments tending to open the joint between the condenser and turbine, themoments producing shearing effect on the joint being disregarded.

By repositioning the expansion element 35 in the manner indicated in Fig. 3, the shearing eifect on the joint between the condenser and turbine are eliminated, as well as the bending moments.

Selection of the proper location for the balanc-v ing expansion element 35 should involve no diiiiculty for one skilled in the art of' condenser design. However, there is shown'in Fig. 4, by way tude of the force exerted at the expansion joint 28. Assuming that the two forces OA and OB 2 are equal in magnitude, the square OADB is determined. The diagonal OD represents the vdirection and magnitude of `the balancing force required, it being only necessary'to lay ofi 'this force as the line OC of a length equal to the diagonal OD and lying along the continuation of the diagonal' OD. The point O at which the three arrows meet'corresponds to the point X in Fig. 3,

While the inventiony has been shown in several vforms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various other changes and modiiications without departing from the spirit thereof, an'd'it is desired, therefore, that onlysuch limitations shall be placed thereupon vas are specifically setforth in the appended claims. f

What is claimed is: v 1

1. In a first device having liquid supplyand `discharge conduits containing expansion joints, vwhich device ris connected toa second device by a relatively rigid joint; expansion apparatus disposed between saidrstdevice and 'a Xed'supnortto reduce moments and reactions on the' relatively rigid joint resulting from moments" produced by hydrostatic thrust in vthe expansion joints of the liquid supply and discharge conduits.

l 2. In a rst device having uid supply and disthrough said tubes; Vwater inlet and outlet connections carried by the waterbox structure; eX- pansion joints joining said inlet and outlet connections to supply and discharge conduits; respectively; an expansion element disposed between the ywaterboir structure and a fixed support; and means providing communication between lthe vexpansion element 'and the waterbox structure, said expansion element being of such size and so positioned with respect to the water- Ybox inlet and outlet connections as to reduce moments and reactions on the relatively rigid connection `resulting from moments produced by vhydrost atic thrustin the expansion joints. 5. Structurev as specified in claim 4 wherein the means providing communication between the ex- Vfpansion element and the waterbox structure charge conduits containing expansion joints, i.

vvvfliichdevice is connected to a second device by a relativelyrigid joint; expansion lapparatus disV- posed between said rst device and a xed support to reduce moments' and vreactions on the `relatively rigid joint resulting from moments produced .by fluid thrust in the expansion joints ,of the iiuid supply and discharge conduits.

3. In a rst device providing a path for circulation of Aliquid and having vliquid-supply and discharge conduits containing expansion joints,

k which device -is-connected to a second device by :a relatively; rigid joint; expansion apparatus disposed between the rst device and stationary sup- .porting means, and means providing communication between theexpansion apparatus .and the liquid circulation; path provided by the ilrstv device, said expansionapparatus being so positioned withrespect to the iirst device as to reducefmoments and reactions on the relatively rigid joint .cluding a Vfor the m ntenan'ce of uid under' pressure with- -in' said hollow structure. A

comprises 'a conduit having a minimum cross sectional larea that is relatively small as compared to' the cross sectional areaof'the'gexpansion element, whereby any pulsations present in water passingthrough the waterbox structure' are prevented from aiecting the expansion element.

6. In combination, iirst and second devices connected Lby a rigid joint, conduits for supplyingfiuid" to and dischargingfluid from the seconfdgdevice; at leastj one of the conduits including ,a main body portion connected byA an expansion joint to a nipple joined to the second device, said nipple being sodisposed' that the pressure of fluid therein provides a thrust actingcn the second `device aridojn the joint between the devices, and

ine'ansfor applying'tokthe seconddevice a coun- 'tenthrust'opposing-ine einer ofsaidfirsttnrust on said 'rigid' joint,k said last-named means comprising a,V hollow Vrstructure interposed between the second 'device andja xed support Vand in- Xp'ansion joint and means providing ERNEST' F. MILLER. 

